Electronic organ having tone generators with two different outputs



3,204,507 ORS 4 Sheets-Sheet l H. E. HOLMAN ETAL ELECTRONIC ORGAN HAVING TONE GENERAT WITH TWO DIFFERENT OUTPUTS sept. 7, 1965 Filed June 27, 1960 Sept. 7, 1965 H. E. HOLMAN ETAL ELECTRONIC ORGAN HAVING TONE GENERATORS WITH TWO DIFFERENT OUTPUTS 4 Sheets-Sheet 2 Filed June 27, 1960 Sept. 7, 1965 H. E. HoLMAN ETAL ELECTRONIC ORGAN HAVING TONE GENERATORS WITH TWO DIFFERENT OUTPUTS Filed June 27, 1960 4 Sheets-Sheet 3 .www MMI WMM; Wm. BNNx www foam

Sept. 7, 1965 H. E. HoLMAN r-:TAL 3,204,507

ELECTRONIC OHGAN HAVING TONE GENERATORS WITH TWO VDIFFERENT OUTPUTS 4 Sheets-Sheet 4 Filed June 27, 19Go Num United States Patent O 3,204,507 ELECTRONIC ORGAN HAVING TONE GENERA- TORS WITH TWO DIFFERENT OUTPUTS Howard E. Holman, John R. Brand, and Marvin Korinke,

Corinth, Miss., assignors to The Wurlitzer Company,

Chicago, Ill., a corporation of Ohio Filed June 27, 1960, Ser. No. 38,968 4 Claims. (Cl. 84-1.'19)

This invention relates generally to the art of the electronic production of music, and more specifically to an electronic organ.

It is the general object of this invention to provide an organ of a dual nature, whereby a great number of varied musical effects may be obtained.

Specifically, it is an object of this invention to provide an organ having electronic tone oscillators `or generators provided with two separate and distinct outputs.

In particular, it is an object of this invention to provide an electronic organ wherein the tone generators each have two outlets, one of which is percussible, and the other of which is not percussible.

It is another object of this invention to provide an electronic organ having different footage stops wherein the percussion can be played on one or more of said stops, while a non-percussion melody is played on another one or more of the stops.

Furthermore, it is an object of this invention to provide an electronic organ having two manuals or keyboards, wherein percussion effects can be played on one keyboard simultaneously with non-percussive effects on the other keyboard.

Other and further objects and advantages of the present invention will be apparent from the following description when taken in connection with the accompanying drawings, wherein:

FIG. 1 is a schematic wiring diagram of certain of the generators or oscillators;

FIG. 1A is a schematic diagram illustrating certain output connections ofthe tone generators;

FIG. 2 is a schematic wiring diagram of the key switches and certain associated controls;

FIG. 3 is a schematic wiring diagram of certain filters and pedal keyboard generators; t

FIG. 4 is a vertically downward extension of FIG. 3 schematically illustrating the stop tab rail; and

FIG. 5 is a block diagram showing certain terminal stages of the organ.

The present organ utilizes master and slave type oscillators, and is what is generally termed a divider type organ. Specifically, one octave of master oscillators of great stability is provided. Each of theser master oscilllators stabilizes a plurality of slave or divider oscillators, each of which can be of much less inherent stability than the master oscillators, or which might not even be capable of independent oscillation. The speciiic oscillators in the present organ are fully disclosed, along with the theory of operation thereof, in the copending application of John R. Brand, Serial No. 28,341, tiled May l1, 1960, for Electronic Musical Instrument Oscillator.

A summary of the oscillators suticient for an understanding for purposes of this case is set forth hereinafter, and for this purpose, reference should be had to FIGS. 1 and 1A. A master oscillator is designated generally by the numeral 10. A string of divider oscillators 12, 14, 16 and 18 is connected to and controlled by the master oscillator 10. The first slave or divider oscillator 12 is controlled directly by the master oscillator 10, while the second slave or divider oscillator 14 is controlled by the rst slave or divider oscillator 12, etc.

The master oscillator is of the Hartley type and includes a vacuum tube 20. Particular attention should 3,204,507 Patented Sept. 7, 1965 ICC be paid to the vacuum tube 20 since it is of an extraordinary type comprising a single cathode 22, a single control grid 24, and two plates 26 and 28. This is not the common usage of beam forming plates of a pentode as auxiliary plates, nor is it any other such inferior eX- pedient. On the contrary, this is a newly developed tube, a 12FQ8, having marked advantages over anything in the prior art. The cathode 22 is directly grounded, while the rst plate 26 is connected to a junction point 30. The junction point 30 is connected through a plate load resistor 32 to a B+ supply line 34. The junction 30 is also connected through a coupling capacitor 36 to the tuned circuit 38 comprising a xed capacitor 40 and a variable or tunable inductance 42. The opposite end of the tuned circuit is connected through a capacitor 44 to the grid 24. The grid is also connected through a resistor 46 to a vibrato connection 48.

The inductance 42 is tapped at twenty-one percent of the total turns from top to bottom, and the tap is grounded. A grounded resistor S4 is connected to a tone output or collector connection 56, to shunt the latter and provide isolation. The connection 56 is also connected through a capacitor 58 to the aforementioned junction 30. The resistor 54 and capacitor 58 form a differentiating network which causes the output at 56 to have a much higher harmonic complement than the signal at the plate of the oscillator.

The master oscillator 10 operates in a condition approachingclass C, and the capacitive loading of the plate through the capacitor 58 to ground through the resistor 54 and through the capacitor 36 to ground through the inductance 42 produces substantially a saw tooth wave form on the plate.

Thus the output as applied to the collector or output connection 56 through the diiferentiating network capacitor 58 to resistor 54 is rich in harmonic content, and is well suited for suitable ltering to produce true musical tones.

A negative potential is applied to the second plate 28 through a resistor 60 from a bus 62 to prevent plate 28 from conducting on peaks of A.C. signals that may be coupled to it through capacitors 70 and 74 hereinafter set forth. The second plate 28 is connected through a resistor 64 to an output connection 66 through which plate potential is supplied to plate 28, and which is shunted to ground by a capacitor 68. The capacitor 68 serves in connection with a keying resistor and key switches to suppress key clicks and pops.

The plate 28 is coupled through a capacitor 70 to an output connection 72 (coded as a triangle), and is connected through a coupling capacitor 74 to an output bus 76.

Oscillation of the master oscillator 10 through the Hartley circuit as just described, including the cathode 22, grid 24 and plate 26, will produce oscillations of the same frequency on the plate 28 whenever a positive voltage is applied at point 66. These oscillations will be of a saw tooth wave form. The output of plate 28 is adapted to a plurality of separate treatments, as indicated by the connections 66 and 72, and by the output bus 76, all as will be discussed hereinafter.

Reference should now be had to the second divider oscillator 12 as illustrative of all of the divider or slave oscillators. In particular, the slave or divider oscillator 12 includes a tube 78 of the same type as the tube 20, including a cathode 80, a control grid 82, and two independent plates 84 and 86. Preferably there are two such tubes contained in a single envelope, and hence fragments of the second tube are shown in dashed lines in each inst-ance, The cathode is grounded, while the plate 84 is connected by a plate load resistor 88 to the aforementioned B-l- -bus 34. The second plate 86 `is connected to output circuits in the same manner as the second plate of the tube 20, including an output connection 91, .an output connection 92, and the bus '76, the connections thereto being made in the same manner as in the case of the master oscillator.

The grid 82 is connected through a capacitor 39 and a resistor 90 to the plate 26 of the tube 20, being driven by the wave form appearing on that plate. The grid also is connected to ground by a capacitor 92, and further is connected to a resistor 94. The resistor 94 is connected to a junction 96, and this junction is in turn shunted to ground by a capacitor 98. This junction is also connected to a resistor 160, and is connected through a resistor 102 to a bias bus or line 103 having a potential of -3 volts thereon.

The resistor 100 is connected to a junction 184, and this junction is connected through a wire 106 and a resistor 103 to the grid of the oscillator tube in the next divider stage 14. The junction 194 also is connected to a capacitor 110. This capacitor is connected to the plate 84 of the tube 78, and also is connected to a capacitor 112 leading to an output connection 114, represented as a square. The output connection 114 is shunted to ground through a resistor 116.

The divider oscillator 12 operates somewhat in the manner of a phase shift oscillator, and it is believed that the exact theory of operation need not be set forth at this point. Sufce it to say that this oscillator operates at half the frequency of the master oscillator 1t), and produces a substantially saw tooth wave form.

The succeeding slave or divider oscillator 14, 16 and 18 each operate at half the frequency of the preceding oscillator and with a saw tooth wave form output.

Before passing on to the key switching, reference should be made to FIG. 1a. In this figure, it will be observed that various of the output connections 72 from the second plate 28, hereinafter referred to as the percussible plate, are connected together in groups of six to group output connections 118, and respectively identified as group 1, group 2, etc. The final group, group 8 has fourteen connections thereto, and it will be observed that there is thus `a total of sixty-one notes.

Reference now should be had to FIG. 2. In this iigure, the keyboards are schematically illustrated from the rear thereof, whereby the treble is at the left, and the bass is at the right. The upper keyboard is disposed at the top of the ligure, while the lower keyboard is at the bottom thereof. The upper keyboard comprises a fixed rod 120 for the four foot stop, an underlying fixed rod 122 for the 51/3 foot stop, and an underlying fixed rod 124 for the sixteen foot stop. The rods are of insulating material, and each is provided along the upper edge thereof with a conductive insert extending through an insulating panel 126 at the left end of the assembly. Thus, the rod 120 is provided with a conductive insert 128, the rod 122 is provided with a conductive insert 130, and the rod `124 is provided with a conductive insert 132. The connections of the conductive inserts to the stop tablets will be discussed hereinafter in connection with a subsequent figure.

Associated with each of the fixed rods 120, 122 and 124 there is a plurality of flexible contacts represented by the squares 134. These squares correspond to the nonpercussible outputs at the squares 56, in FIG. 1. Connection is made to them from the squares 56 through resistors 136 to provide proper isolation. The squares are provided with numbers, in accordance with the number of the tone generator having the output applied to the movable contact. As will be apparent in FIG. 2, the upper twelve notes are repetitive of a similar octave appearing immediately to the right thereof, and the correspondingly numbered squares are simply directly connected electrically by jumper wires. This is common practice in the organ ield, and is done since there are only sixty-one tone generators, while there is room for another octave of keys at the top of the scale associated with the four foot 4 stop. The same situation prevails in connection with the 51/3 foot stop rod 122, wherein seven generators are repeated.

It will further be observed that certain of the tone generators are connected for switching in more than one stop. In such instances, the connections are through a resistor to one movable Contact, and from that Contact through another resistor to a similar numbered contact. For example, at the extreme left end of the 51/3 foot stop, connection is made through the leftmost resistor 136 to signal contact S6, and from signal contact 56 through the sixth resistor from the left associated with the four foot rod, and to the contact numbered 56. Only a few of the wires are shown as exemplary, as is also true with the direct connection jumper wires previously mentioned. The resistors 136 are provided for purposes of isolation.

Beneath the three fixed rods 120, 122 and 124 there are three rotating rods, respectively comprising a rotating rod for a four foot stop 138, an eight foot stop rotating rod 140, and a sixteen foot stop rotating rod 142. The rotating rod 138 has a conductive insert 144 (the rotating rods are of the same general construction as the iixed rods) connected through a spring 146 to a resistor 148 on the insulating end panel 126. The resistor is connected to a common collector 150. The conductive insert 152 of the rotating rod 140 is connected through a spring 154 to a resistor 156, which also is connected to the collector 150. Similarly, the rotating rod 142 is provided with a conductive insert 158 which is connected through a spring 160 to a resistor 162, the resistor being in turn connected to the collector 150. The rotating rods are arranged to be contacted by iiexible wire or Whisker contacts indicated at 164, and appropriately labeled as to the respective generators. Each of the contacts 164 is connected to one of the connections 66 of FIG. l from the percussible plate of the corresponding generator. As in the case of the fixed rod stops, similarly numbered contacts are interconnected, and certain contacts are repeated even in the same stop. In this instance, the connections are direct with no isolating resistors.

Each key of the keyboard has associated therewith six movable contactors, representing the vertically aligned squares 134 and circles 164 in any vertical row of FIG. 2. All of these are depressed when a key is depressed. The contactors associated with the rotating rods either make electrical contact, or do not, according to the position of rotation of the rods. Such key switch arrangements are widely known in the art, and one suitable ar rangement, for example, is to be found in Osborne et al. U.S. Patent 2,846,916, Organ Stops and Key Switches.

One additional rotating rod 166 is positioned below the three previously mentioned rotating rods. The conductive insert 168 in this rod is connected through a spring 170 to ground. The contacts 172 associated with the rod 166 are greater in number than are those associated with the previously mentioned rods, and correspond to practically all of the generators of the organ, running from generato-r No. 6 through generator No. 61. All of the contacts 172 at all times engage the rod 166. These contacts are iiexible conta-cts, but they are fixed in position, and not controlled by the keys. Thus, when the rod 166 is rotated to bring the conductive insert 168 to the upper edge thereof, all of the contacts 172 engage the insert 168, whereby to ground all of these contacts. Such grounding is to control biasing of the organ at another point to cause tones to be sustained.

As previously mentioned, there is also a lower keyboard. There are three rods in the lower keyboard, the uppermost of which is a fixed rod 174 having a conductive insert 176. A rotating rod 178 having a conductive insert 180 underlies the xed rod 174. An additional fixed rod 182 having a conductive insert 184 underlies the two previously mentioned rods, 174 and 178. The rod 174 cornprises a non-percussible four foot stop, the rod 178 corn prises a percussible eight foot stop, and the rod 182 comprises a non-percussible eight foot stop.

The connection of the conductive insert 176 is through an insulating end panel 186, and connections from that point will be discussed hereinafter in connection with another gure. The conductive insert 180 is connected through a spring `188 to a resistor i190 on the panel 186, and a wire 192 leads from the top of the resistor 190 to the bottom of the resistor 162 through the wire 150. As will be observed, the bottoms of the resistors 148, 156 and 162 are connected in parallel by a wire 194. A connection is indicated at `196 between .the wires 150 and 192, and this connection is provided with :a --l-300 volts from the amplifier.

The construction of the switch contacts of the lower keyboard is similar to that of the upper keyboard. Thus, Verically aligned contacts are simultaneously operated by the same key. Non-percussible contacts again are represented by squares, in this instance identied by the numeral 198, while percussible contacts again are represented by circles, this time identified by the numeral 200. Connection is made to the contacts 198 through resistors 202 as previously described.

Referring now to the open portion in the center portion of FIG. 2 between the upper and lower keyboard, there is provided a stop tablet 204 which is connected as indicated by the dashed line 206 to rotate the four foot stop rod 138. The stop tablet 204 comprises what is known in organ terminology as an upper to upper coupler. A second stop tablet 288 is connected as indicated by the dashed line 210 to rotate the sixteen foot stop rod 142. This stop tablet is what is known in organ terminology as an upper to upper coupler. It will be noted that the rods 138 and 142 are normally inactive, until their respective four foot and sixteen foot couplers are actuated.

A third stop tablet 212 is connected by a mechanical connection as indicated at 214 to rotate the eight foot stop rod 140. It will be observed that this rod is normally active, i.e., the conductive insert 152 is normally in position to be engaged by the contacts 164. However, when the stop tablet 212 is actuated, the rod is moved to inactive position. Accordingly, the stop tablet 212 comprises an upper eight foot oti stop tablet. Stop tablet 216 comprises a control for producing either medium or long sustain, and controls a movable switch contact 218 which is normally spaced from, but which is movable into engagement with a grounded switch contact 220. A mov` able contact 218 is connected through a resistor 222 to a junction 224 which is shnnted to ground by a capacitor 226. The junction is connected to a source of 130 volts from the amplifier, and is provided with `an output connection 228 which is adapted to supply either 5 volts or -130 volts. Normally, with the switch 218, 220 open, the output connection 228 is at -130 Volts. However with the switch closed, the resistor 222 becomes a `part of a voltage divider (the remainder of which is not shown) and the voltage at the output connection 228 is dropped to -5 volts.

' A fifth stop tablet 230 comprises a sustain on-off switch, and is mechanically connected as indicated at 232 to the rotating rod-166 to effect rotation thereof.

A- sixth stop tablet 234 is mechanically connected as indicated 2111.236 to the rotating rod 178 to effect rotation thereof. The stop tablet 234 comprises an upper to lower coupler for the eight foot stop.

Yet another stop tablet 238 comprises a master volume control. The master Volume control stop tablet 238 is connected to a movable switch contact 240 having a connection at 242 to the amplier. The movable contact 240 normally engages a xed grounded contact 244. In such position, a particular point (not shown) in the ampliier Ais grounded. When the stop tablet 238 is manipulated `to the full position'the switch 240, 244 is opened to remove ground from the particular amplifier point mentioned, and the amplifier then has a higher gain to produce fuller or louder tones.

yWhenever the organ is turned on, the oscillators all are oscillating, and the output from the non-percussible plates (the leftmost plates, such as 26, 84, etc. in FIG. 1) constantly supply an output to the respective squares or output connections such as 56, 114, etc. Thus, non-percussible output is always available at the contacts 134, and it is only necessary to depress a corresponding key to apply an output to one or more of the iixed rod inserts 128, 130, 132, which serve as collectors, and which are connected as hereinafter set forth, to produce organ tones. However, the right hand or percussible plates, such as 28, 86, etc. are normally inoperative or devoid of signal, due to the absence of potential, or more specifically due to the cutting off negative potential of -5 or 130 volts as supplied to the bus line 62 from the sustain output connection 228, it being understood that the bus 62 is permanently connected to the connection 228. When one of the rotating rods is turned to playing position, and an appropriate key is depressed, the +300 volts appearing at 196 is connected through the respective switch contact to apply a high positive potential at the corresponding percussive plate connection, such as 66, 91, and other connections indicated by a similar small circle. This causes 'the corresponding plate to conduct, thus supplying a percussive output signal to the line 76, and to the corresponding triangular coded output connection, as 72, 92, etc.

Reference now should be had to FIG. 3. In this figure, the triangles 118 are the same as the group or collector connections of the oscillators, as previously discussed in connection with FIG. la. These group connectors or collectors 118 are numbered by groups from bottom to `top, corresponding to the numbers from left to right in FIG. la. The group connectors or collectors 118 are shunted to ground by capacitors 246 and are respectively 'connected to wires 248. The wires 248 continue down in FIG. 4 to a like plurality of movable switch contacts 250 which are connected to and movable by an eight foot flute stop tablet 252. In addition to the ilexible or movable flute contacts 250, the iiute stop tablet controls a pair of outer movable contacts 254 which are connected to a ground line 257. All of the contacts 250 and 254 normally engage a transverse fixed or shorting contact 256. Accordingly, all of the wires 248 normally are connected to ground. This prevents the percussible plate outputs appearing at the various group collectors or connectors 118 from playing through unless the ilute stop tablet is moved to open position, thereby opening the ground connection to the wires 248.

Returning to FIG. 3, the wires 248 extend up to respective resistors 258, which are respectively connected to a plurality of wires or conductors 260, which in turn respectively lead to the control grids of respective triode tube sections 262, conveniently comprising the halves of dual triodes. lThe output of each tube 'section is con- 'nected to a respective tuned filter circuit 264 and the outputs of all of the tuned filter circuits are connected to a common collector 266 which is in turn connected to a shielded lead or cable 268.

Thus, it will be seen that each of the tuned flute iilters l264 receives the output or signal from six percussible -of operation of the filters, and further discussion thereof are found in the copending application of John R. Brand and I. H. Hearne, entitled Tone Filters, Serial No.

V37,243 filed June 20, 1960, issued July 23, 1963 as U.S.

Patent 3,098,407.

Returning now to FIG. 4, immediately to the right of `the wires 248, there will be seen a connection 270 from -the generator percussible signal bus 76 of FIG. 1.

This

connection is shunted to ground through a resistor 272, and is connected by a wire 274 to a fixed contact 276 associated with a trumpet eight foot stop tablet 278. The movable contact 280 associated with the trumpet stop tablet normally engages a grounder fixed contact 282, but is movable away from this contact into engagement with the contact 276. The movable contact 280 is connected through a wire 284, shunted to ground by a resistor 286, to the grids of the triode tube sections 262 associated with the second and fourth filters 264.

The connection 270 further leads through a wire 288 to a fixed contact 298 of a stop switch including a movable switch contact 292 fixed to and controlled by an eight foot oboe stop tablet 294. The movable contact 292 normally engages a grounded fixed contact 296, but is movable away from the grounded Contact into engagernent with the contact 290 by movement of the stop tablet 294. The movable contact 292 is fixed to a wire 298 which leads to the grids of the vacuum tubes 262 feeding filters Nos. 1 and 3 of the filter 264. The wires 298 is shunted to ground by a resistor 300.

The circuitry shown at the bottom of FIG. 4 is in its actual physical construction aligned with the upper portion horizontally. It has been offset in FIG. 4 in order to fit on the drawing sheet. It will be observed that this section of the instrument includes three stop tablets respectively comprising a vibrato on-otf stop tablet 302, a vibrato speed stop tablet 304, and a vibrato depth or intensity stop tablet 306. These stop tablets are respectively connected to appropriate switches which are interconnected with a vibrato generator or oscillator 308 having an output connection at 310. The vibrato oscillator and the connections thereto are more or less conventional in nature, and it is thought that further detailed discussion is unwarranted. It will be understood that the vibrato output connection 310 is directly connected to the vibrato bus 48 leading to the generator grids, as shown in FIG. 1.

Reference now should be had to the lower left hand portion of FIG. 3 and to the corresponding upper left hand portion of FIG. 4. Thus, an input signal is provided at 312 to a pedal amplifier 314 comprising two stages of triode amplification. The pedal connections comprise the subject matter of a copending application Holman et al. Serial No. 37,418, filed .Tune 20, 1960, for Switching Circuit for Electronic Musical Instrument. It is sufficient to say here that there are pedals on the organ having switches for connecting the output from various of the master and slave oscillators, typically the lower octave thereof, to the input connection 312. The grids of the two amplifier stages are provided with -22 volts bias, as indicated at 316, from the amplifier (not shown).

The output of the two-stage amplifier 314 is coupled through a capacitor 318 and a wire 320 to an Eccles- Jordan divider 322 of generally conventional construction, the grids of which are provided with -134 volts potential as indicated at 323. The first Eccles-Jordan divider corresponds to a sixteen foot pedal stop, while a second stage 324 further dividing the output of the stage 322 corresponds to an 8 foot pedal stop. The major distinction from ordinary EcclesJordan circuits is that the second triode half of each divider is provided with an extra plate, respectively identified as 326 and 328. The triode tube sections having the extra plates are of the type previously discussed in connection with the generators, specifically each being one half of a 12FQ8. These plates are respectively connected to op posite sides of a resistance-capacitance network 330,

'to which a positive voltage is applied at 332 whenever any pedal is depressed to play a pedal tone. The plates 326 and 328 are respectively connected at the filter 330 to output wires 334 and 336 leading through appropriate resistors and capacitors respectively to switches controlled by a sixteen foot pedal stop tablet 338 and an eight foot pedal stop tablet 340. The switches normally are grounded, and hence shunt out any output of the pedal dividers. When the grounding switches are opened individually or at the same time, connection is made from the wires 334 and 336 through a resistance-capacitance filter 342 to a two position switch controlled by a pedal voice stop tablet 344. Either of two filter sections is connected by this switch, either for a principal voice or for a major bass, to a bus or collector 346 leading to a line 348 having an output connection 350 leading to the amplifier (not shown).

The collector 346 is connected through a series of switches each having a grounding resistance, and respectively controlled by a pedal volume, full stop tablet 352, a pedal volume, medium stop tablet 354, and a pedal volume, soft stop tablet 356. There are two additional pedal stop tablets, namely a pedal sustain on-ofi stop tablet 358, and la pedal sustain, medium-long stop tablet 360, respectively comprising switches which act through resistors either to shunt to ground or not to shunt to ground a wire 362 leading to the positive pedal voltage at 332, whereby to control decay of voltage at this point.

The remaining stop tablets are connected to resistancecapacitance filters for wave or tone shaping of the various outputs of the non-percussible tone generators. Thus, upper keyboard fixed rod conductive insert 132 of FIG. 2 is connected in FIG. 4 to an input connection 364 leading through one of the aforesaid R-C filters 366 to a series of three switches respectively operated by three stop tablets, namely a sixteen foot solo stop tablet 367, a sixteen foot bourdon stop tablet 368 and a sixteen foot trombone stop tablet 370. The solo stop tablet switch merely removes a resistor from a voltage divider to increase the intensity of the sixteen foot stop, thereby making it stand out as a solo stop, when so desired. The sixteen foot bourdon and trumpet stop tablets both control switching suitably to filter the tones at the input 364, and to connect them directly to the connector 346, and hence to the output 350.

Immediately to the right of the stop tablets just enumerated, there is an eight foot solo stop tablet 372, which also controls the number of resistors in a circuit to make -it possible for the eight foot stop to sound out as a solo stop, when so desired.

The remaining eight foot stops of the upper keyboard are supplied from the percussible signal bus connection at 270, previously discussed in connection with the trumpet and oboe eight foot stops. The stops comprise respectively a diapason (the characteristic organ tone), and a string stop. The corresponding stop tablets 374 and 376 respectively control switches interconnected with an R-C network 378 either to ground the signals from respective parts of the network, or to connect them to the collector 356 and hence to the output 350.

Connection is made from the conductive insert of the 51/3 foot fixed rod of the upper keyboard (FIG. 2) to an input connection 376 leading to another R-C filter 3718. The output of the R-C filter is connected through a switch controlled by a 5% foot quint stop tablet 380. There is also a solo 51/3 foot stop tablet 382, as will be understood.

The conductive insert 128 of the four foot fixed rod of the upper keyboard (FIG. 2) is connected to an input connection 384 (FIG. 4) leading to another R-C filter 386. The R-C filter is connected by means of a switch controlled by an orchestra iiute four foot stop tablet 387 to the collector 346. Connection is made direct from the input 384 to the collector through a switch controlled by a violina four foot stop tablet 388. There is again provided a four foot solo stop itablet 390.

The conductive insert 184 of the eight foot fixed rod 182 of the lower keyboard is connected to an input connection 392 which leads to another R-C filter 394. Various switches are interconnected with this filter, includving a solo eight foot stop 396 switch, and switches respectively controlled by a melodia eight foot stop tablet 398, a cello stop tablet eight foot stop 400, and an eight foot horn stop tablet 402. Connection als-o is made from -the conductive insert 176 of the four foot fixed rod 174 of the lower keyboard to an input connection 404 which is interconnected with an R-C filter 406. There are three switches interconnected with this R-C filter, and one of these is controlled by a four foot solo stop tablet 408. The other two switches lead to the collector line 346, and are respectively connected by a four foot ha-rmonic flute stop tablet410, and a four foot string stop tablet 412.

Reference now should be had to FIG. for final treatment of the organ tones. Thus, there is a preamplifier first stage indica-ted at 414, with the tones from .the R-C filters connected thereto at 350, the same numeral being used as for the output connection in FIG. 4 for continuity. The first stage preamplifier is connected to a second stage preamplifier, and the tuned filter input is applied thereto at 268, a number again being duplicated. A resistor 418 shunts the input to the second preamplifier stage 416, and is grounded through .the master volume control switch 240, 244, previously discussed, whereby to control the overall volume of the organ.

The second stage of the preamplifier is connected through a potentiometer 420 to a power amplifier 422. The potentiometer 420 is controlled by the usual swell pedal of the organ. Finally, the power amplifier 422 drives a loudspeaker 424. As will be understood, the loudspeaker 424 is simply illustrative of what may be a rather considerable array of loudspeakers.

By means of the couplers previously described, which rotate the various rotatable rods, it is possible to play on the upper keyboard, individually or combined, the 16 and 4' pitches of the 8 voices, namelyr flute, diapason, string, trumpet and oboe. One is further enabled to play on the lower keyboard at the 8 pitch the 8' voices of the upper keyboard, either alone or in combination with voices of the lower keyboard. This in efiect adds five tonalities to the resources of the lower keyboard. It further enables one to play on the lower keyboard any or all of the 8 voices of the upper keyboard or to play on the upper keyboard a melody using any 16', 51/3, and/o1' 4 voice without the 8 tonality being included in the combination. Furthermore, one may use the 8 solo control of the upper keyboard in conjunction with the couplers to produce the increased intensity that the solo control affords.

In effect, the coupling system adds ten additional individual tonalities at different pitches to the resources of the upper to upper 16 coupler, one can automatically add, to the lower keyboard with two intensities of each. With the upper to upper 16 coupler, one can .automatically add, or couple, to the 8 registration being played on the upper keyboard, a 16', or octave lower, pitch of the same tonality.

With the upper to upper 4' coupler, one automatically adds, or couples, to the 8 registration being played on the upper keyboard, the 4', or octave higher, pitch of the same tonality.

With the upper 8' off control, the 8 pitch is removed `from the upper keyboard. This is useful when it is desired to play only the 16 and/ or 4 pitch of any of the 8 voices (flute, diapason, string, trumpet or oboe). This is accomplished by using the upper to upper 16 coupler with the upper 8 off for 16', and/ or upper to upper 4 coupler with the upper 8 off for 4.

With the upper to lower 8' coupler, one can add, or couple, to the lower keyboard at the 8 (unison) pitch all of the 8 registrations set on the upper keyboard. With the further use of the upper 8 off control, one can play a solo on the upper keyboard using a 16', 5%', and/ or 4' voice with an accompaniment on the lower keyboard (by means of the upper to lower 8 coupler) using the tonalities of any of the upper keyboard 8 voices.

Thus it will be seen that by the provision of an organ 1f) which is of a dual nature, a great multiplicity of different effects can be obtained. There is but a single generator for each note, and yet distinctly different and completely isolated outputs are obtained. The two outputs are handled separately to provide separate effects, and subsequently are recombined in a common amplifier.

Various changes in structure relative to the exemplary embodiment hereinbefore set forth will no doubt occur to those skilled in the art, and will be understood as forming a part of this invention insofar as they Ifall within the spirit and scope of the appended claims.

We claim:

1. An electronic organ comprising a plurality of tone generators respectively generating complex electrical oscillations corresponding to the tones of an organ, each tone generator including a vacuum tube having a common cathode, a common control grid, a first plate and a second like plate, means normally supplying positive potential to each first plate, each second plate normally having no positive potential applied thereto, means providing potential return paths connected to said cathode and to said grid, means respectively including said plates providing a plurality of isolated outputs for each tone generator, a first output of each tone generator being interconnected with said first plates and normally having oscillations appearing thereon at all times, a second output of each tone generator being interconnected with said second plate and having no oscillations thereon in the absence of application of positive potential, a plurality of movable playing key controlled switch means each comprising a ganged plurality of normally open movable switch contacts, a plurality of fixed common collectors each of which is selectively engageable by all corresponding ones of said movable key switch contacts, a plurality of movable common collectors movable to and from position for engagement by all of corresponding others of said movable switch contacts, means connecting the first tone generator outputs to movable switch contacts engageable with the fixed common collectors, means connecting the second tone generator outputs respectively to movable switch contacts engageable with the movable common collectors, a source of positive potential connected to the movable common collectors, selective closing of said movable switch contacts against said movable common collector thereby selectively applying positive potential to said second plates and rendering said second outputs selectively operable, a plurality of different filter paths having input and output means, means connecting the fixed common collectors to different ones of said filter path input means, means connecting said second tone generator outputs together in half octave groups, means selectively connecting said half octave groups respectively to predetermine ones of said filter input means, common collector means connecting the second tone generator outputs to different additional ones of said filter path input means, amplifier means connected to said lter path output means for amplifying the electrical oscillations, and electro-acoustic translating means connected to said amplifier means to convert the amplified electrical oscillations into audible organ tones.

2. An electronic organ comprising a plurality of tone generators respectively generating complex electrical oscillations corresponding to the tones of an organ, each tone generator including a vacuum tube having a common cathode, a common control grid, a first plate and a second like plate, means normally supplying positive potential to each first plate, each second plate normally having no positive potential applied thereto, means providing potential return paths connected to said cathode and to said grid, means respectively including said plates providing at least a first output and a second output for each tone generator, said outputs being isolated from one another, each of said first outputs being interconnected with said first plate and normally having oscillations appearing thereon, said second outputs respectively being interconnected with said second plates and normally having no oscillations appearing thereon and requiring application of positive potential to cause oscillations to appear thereon, common collector bus means permanently connected to said second outputs, a first plurality of playing key controlled switch means corresponding to an upper manual, a second plurality of playing key controlled switch means corresponding to a lower manual, each of said first and second plurality of playing key controlled switch means comprising a ganged plurality of movable normally open key switch contacts, at least one fixed common collector positioned for engagement by all of corresponding ones of said upper manual movablekey switch contacts, at least one fixed common collector positioned for engagement by all the corresponding ones of said lower manual movable key switch contacts, means respectively interconnecting the lirst outputs and the key switch contacts engageable with the fixed common collectors, a plurality of movable common collectors positioned adjacent other corresponding ones of said upper manual movable key switch contacts for contact .thereby upon movement thereof, at least one predetermined one of said movable common collectors normally being positioned for contact, a plurality of movable common collectors positioned adjacent other corresponding ones of said lower manually movable key switch contacts and movable between positioned for Contact and non-contact by said other corresponding ones of said lower manual key switch movable contacts upon movement thereof, each of said movable common collectors including an insulating rotatably mounted rod and a conductive insert extending longitudinally and exposed laterally thereof, at least one of said last mentioned movable common collectors corresponding to said predetermined movable common collector being normally positioned for non-contact, a source of positive potential, means connecting said source of positive potential to said movable common collectors, selective closing of said movable switch contacts against said movable common collector thereby selectively applying positive potential to said second plates and rendering said second outputs selectively operable, amplifier means, filter means connecting said common collector bus to said amplifier means, means connecting the fixed common collector to said amplifier means, means in addition to said filter means connecting the second outputs together in halt` octave groups, means selectively connecting said half octave groups respectively to predetermined filter means and to the amplifier means, and electro-acoustic translating means for converting the amplified oscillations into audible organ tones.

3. An electronic organ as set forth in claim 2 and further including atleast two ditferent filter paths, the means connecting the fixed common collectors to said amplifier means including one of said filter paths, and the means connecting the second output to the amplifier means including a second of said iilter paths.

4. An electronic organ as set forth in claim 1, wherein the additional ones of the filter paths comprise a plurality of inductance-capacitance filters, and wherein the remaining filter paths comprise a plurality of resistance-capacitance filters.

References Cited bythe Examiner UNITED STATES PATENTS 1,597,398 8/26 Wilson 331-184 2,506,723 5/50 Larsen 84-1.l9 X 2,539,826 1/51 George SLi-1.17 X 2,681,585 6/58 Hanert Slt- 1.22 2,906,157 9/59 Peterson 84-1.17 X 3,068,735 12/ 62 Anderson 84-1.19 X

ARTHUR GAUSS, Primary Examiner.

CARL W. ROBINSON, GEORGE N. WESTBY, JOHN W. HUCKERT, Examiners. 

1. AN ELECTRONIC ORGAN COMPRISING A PLURALITY OF TONE GENERATORS RESPECTIVELY GENERATING COMPLEX ELECTRICAL OSCILLATIONS CORRESPONDING TO THE TONES OF AN ORGAN, EACH TONE GENERATOR INCLUDING A VACUUM TUBE HAVING A COMMON CATHODE, A COMMON CONTROL GRID, A FIRST PLATE AND A SECOND LIKE PLATE, MEANS NORMALLY SUPPLYING POSITIVE POTENTIAL TO EACH FIRST PLATE, EACH SECOND PLATE NORMALLY HAVING NO POSITIVE POTENTIAL APPLIED THERETO, MEANS PROVIDING POTENTIAL RETURN PATHS CONNECTED TO SAID CATHODE AND TO SAID GRID, MEANS RESPECTIVELY INCLUDING SAID PLATES PROVIDING A PLURALITY OF ISOLATED OUTPUTS FOR EACH TONE GENERATOR, A FIRST OUTPUT OF EACH TONE GENERATOR BEING INTERCONNECTED WITH SAID FIRST PLATES AND NORMALLY HAVING OSCILLATIONS APPEARING THEREON AT ALL TIMES, A SECOND OUTPUT OF EACH TONE GENERATOR BEING INTERCONNECTED WITH SAID SECOND PLATE AND HAVING NO OSCILLATIONS THEREON IN THE ABSENCE OF APPLICATION OF POSITIVE POTENTIAL, A PLURALITY OF MOVABLE PLAYING KEY CONTROLLED SWITCH MEANS EACH COMPRISING A GANGED PLURALITY OF NORMALLY OPEN MOVABLE SWITCH CONTACTS, A PLURALITY OF FIXED COMMON COLLECTORS EACH OF WHICH IS SELECTIVELY ENGAGEABLE BY ALL CORRESPONDING ONES OF SAID MOVABLE KEY SWITCH CONTACTS, A PLURALITY OF MOVEABLE COMMON COLLECTORS MOVABLE TO AND FROM POSITION FOR ENGAGEMENT BY ALL OF CORRSSPONDING OTHERS OF SAID MOVABLE SWITCH CONTACTS, MEANS CONNECTING THE FIRST TONE GENERATOR OUTPUTS TO MOVABLE SWITCH CONTACTS ENGAGEABLE WITH THE FIXED COMMON COLLECTORS, MEANS CONNECTING THE SECOND TONE GENERATOR OUTPUTS RESPECTIVELY TO MOVABLE SWITCH CONTACTS ENGAGEABLE WITH THE MOVABLE COMMON COLLECTORS, A SOURCE OF POSITIVE POTENTIAL CONNECTED TO THE MOVABLE COMMON COLLECTORS, SELECTIVE CLOSING OF SAID MOVABLE SWITCH CONTACTS AGAINST SAID MOVABLE COMMON COLLECTOR THEREBY SELECTIVELY APPLYING POSITIVE POTENTIAL TO SAID SECOND PLATES AND RENDERING SAID SECOND OUTPUTS SELECTIVELY OPERABLE, A PLURALITY OF DIFFERENT FILTER PATHS HAVING INPUT AND OUTPUT MEANS, MEANS CONNECTING THE FIXED COMMON COLLECTORS TO DIFFERENT ONES OF SAID SECOND TONE PATH INPUT MEANS, MEANS CONNECTING SAID SECOND TONE GENERATOR OUTPUTS TOGETHER IN HALF OCTAVE GROUPS, MEANS SELECTIVELY CONNECTING SAID HALF OCTAVE GROUPS RESPECTIVELY TO PREDETERMINE ONES OF SAID FILTER INPUT MEANS, COMMON COLLECTOR MEANS CONNECTING THE SECOND TONE GENERATOR OUTPUTS OF DIFFERENT ADDITIONAL ONES OF SAID FILTER PATH INPUT MEANS, AMPLIFIER MEANS CONNECTED TO SAID FILTER PATH OUTPUT MEANS FOR AMPLIFYING THE ELECTRICAL OSCILLATIONS, AND ELECTRO-ACOUSTIC TRANSLATING MEANS CONNECTED TO SAID AMPLIFIER MEANS TO CONVERT THE AMPLIFIED ELECTRICAL OSCILLATIONS INTO AUDIBLE ORGAN TONES. 